Quick change liquid metering device

ABSTRACT

An improved procedure and apparatus for introducing liquids within a thermoplastic or thermoset production system are provided. Such an inventive apparatus comprises a storage tank for the desired liquid, a device which connects to a flow channel (such as a manifold or pipe) through which the target thermoplastic or thermoset composition is flowing, and a transfer line connecting the storage tank with the connecting device. The connecting device itself easily attaches and detaches to the flow channel through a spring-loaded or sliding-lock mechanism. Such a novel apparatus permits an ease in changeover from one liquid to another without the need for time-consuming cleaning and without complicated shut-off, removal, and replacement steps. Furthermore, such an apparatus allows for quick start-up, a drastic reduction in time required for changeover, and, with the connecting device being attached directly to the flow channel, a reduction in potential clogging through the unwanted misdirection of thermoplastic or thermoset composition into the connecting device and/or transfer line itself. As noted above, the particular procedure for producing such thermoplastic or thermoset compositions through utilization of such an apparatus is encompassed within this invention as well.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon U.S. provisional application No.60/242,651 filed on Oct. 23, 2000.

FIELD OF THE INVENTION

This invention relates to an improved procedure and apparatus forintroducing liquids within a thermoplastic or thermoset productionsystem. Such an inventive apparatus comprises a storage tank for thedesired liquid, a device which connects to a flow channel (such as amanifold or pipe) through which the target thermoplastic or thermosetcomposition is flowing, and a transfer line connecting the storage tankwith the connecting device. The connecting device itself easily attachesand detaches to the flow channel through a spring-loaded or sliding-lockmechanism. Such a novel apparatus permits an ease in changeover from oneliquid to another without the need for time-consuming cleaning andwithout complicated shut-off, removal, and replacement steps.Furthermore, such an apparatus allows for quick start-up, a drasticreduction in time required for changeover, and, with the connectingdevice being attached directly to the flow channel, a reduction inpotential clogging through the unwanted misdirection of thermoplastic orthermoset composition into the connecting device and/or transfer lineitself. As noted above, the particular procedure for producing suchthermoplastic or thermoset compositions through utilization of such anapparatus is encompassed within this invention as well.

BACKGROUND OF THE PRIOR ART

Thermoplastic and thermoset products are utilized to provide differentarticles and for myriad purposes. For instance, polyester thermoplasticarticles include soft drink bottles, medicine vials, and the like;polyolefin thermoplastic articles include food containers, films, andthe like; polyurethane thermosets include, without limitation, slabstockfoams, carpet underlays, surface coatings, and the like. In order toproduce such articles, it is necessary to heat-melt the basethermoplastic to a liquid or otherwise process a thermoset into whichany number of additives may be present, or, more particularly,incorporated therein. Such additives could include antioxidants,nucleating agents, plasticizers, acid scavengers, brighteners, and, mostpreferably, coloring agents.

With the desire for certain aesthetic qualities within the marketplacefor such products, the addition of colorants within such thermoplasticsor thermosets has become commonplace. As noted above, the introductionof such coloring agents within target thermoplastics is generallyperformed through a pipe (or similar channel) attached simultaneously toboth a coloring agent storage tank and the flow channel (pipe, etc.)within which the plastic pellets are transported. Unfortunately, such aconfiguration has proven difficult in the past, particularly since suchapparati are attached through extensive connecting devices (clamps,screws, seals, etc.) to the target plastic flow channel. Furthermore,the feed lines from the coloring agent storage tanks have not beenconnected adjacent to the flow channel itself; in general, such aconnection from the storage tank is present on a separate shunt pipelocated on the flow channel itself. Thus, the shunt pipe is thecomponent through which the coloring agent must penultimately travelthrough prior to introduction within the target plastic within the flowchannel. In such a configuration, the shunt pipe is susceptible toclogging, requires cleaning after use (particularly prior to utilizationof a different coloring agent through the same shunt pipe), all of whichadds inordinate amounts of time to the already time-consuming procedure.As a result, there is a need to provide a liquid metering device forsuch procedures which foregoes such cleaning requirements, reduces thechances for clogging of coloring agent and/or molten plastic within thefeed line itself, and thus, which provides a more efficient manner forchanging coloring agents (and other liquid additives) during plasticproduction. To date, there have been no such specific developments tosuch a degree within the pertinent thermoplastic or thermoset productionindustry.

Such an introduction of such coloring agents within such target plasticshas, as alluded to above, through rather cumbersome procedures. Forinstance, such methods of introduction have been met in the past throughthe utilization and introduction of colorants through one or more pipesor injectors, arranged consecutively and serially (if a plurality ispresent), through connections (feed lines, etc.) feeding to a manifold,and ultimately onto and/or mixed with pellets or into molten plasticformulations. The pipes or valve assemblies have been disposed in thepast by merely creating a hole in the manifold to which the pipe orvalve assembly is attached. The colorant would then be fed (by pressureor gravity, for instance) through the pipe or valve assembly and emptiedinto the pellet or molten plastic stream travelling through themanifold. These colored mixtures are then generally fed to a furthermixing vessel or, in the instance where pellets are colored, to amelting vessel (such a heated screw, and the like) and fed to thedesired molder, extruder, etc. Such a standard method has proveninefficient and problematic in the past since the utilization of afeeder pipe into the flow channel manifold requires a number of extra,time-consuming procedures upon changeover from one coloring agent toanother. For example, the feeder pipe must be cleaned of excess coloringagent; the target plastic (be it in pellet or molten form) may entersuch a feeder pipe instead of the flow channel manifold (therebycreating potential clogging, flow, and/or waste problems; andinstantaneous shut-off and, more importantly, start-up are nearlyimpossible to accomplish. Furthermore, the connection between thecoloring agent storage tank and the coloring agent feed line (directlyattached to the plastic flow channel manifold) is generally made by arigid or flexible tube which is attached to the feed line, at least,through a cumbersome, rather reliable, device (such as a clamp) whereinthe tube is generally larger in diameter than the feed pipeline. Thus,even flow problems and leak possibilities are increased, and in fact,prevalent, with such a standard traditional configuration. Therefore, itis evident that improvements are highly desired within the industry topermit more efficient and effective introduction of liquid additiveswithin thermoplastic or thermoset formulations and articles.

In the past, custom blends of coloring agents, such as polymericcolorants, were prepared prior to use by mixing two or more “primary”colors prior to incorporation within the target plastic. The componentswould be mixed together using some type of agitator such as a mixer or adrum tumbler. Once the blend was of an appropriate shade it wastransferred to a storage tank for further introduction within the foamsubstrate. Upon completion of coloring with a specific batch ofpolymeric colorant, the previously run color would have to be emptiedfrom the storage tank; the tank would need to be cleaned; and then thenext color to be run in the same tank would have to be charged in thetank. Cleaning of the tanks, feed lines (a.k.a. pipelines), etc., wasfacilitated due to the water-solubility of the polymeric colorants(particularly as compared to pigments); however, the procedures followedwere still considered labor intensive and not cost efficient. Thegeneral practice was then modified to maintain a dedicated tank for eachseparate color (shade) that was to run. This led to a number ofinefficiencies and limitations that were not desirable if a foam orthermoplastic manufacturer was to adequately meet demands in the marketplace.

Polymeric colorants, such as disclosed in U.S. Pat. No. 4,284,729 toCross et al., herein entirely incorporated by reference, were designedto be totally miscible with one another as well as within most plasticcomponents (such as polyols, one of the two main ingredients used toproduce polyurethane materials, isocyanates being the other, forexample). Pigment dispersions, on the other hand, are particulatesdispersed in some type of liquid carrier. They require a high degree ofagitation before they satisfactorily blend together to provide a uniformcolor. Furthermore, they are generally not water-soluble and thus eitherdifficult to clean from certain surfaces or, alternatively, require theutilization of undesirable organic solvents (methylene chloride, and thelike, for example) for removal. Additionally, colorants such as aciddyes, solvent dyes, and the like, are also utilizaed for the coloring ofthermoplastics and thermosets which also tend to pose the same generalcleaning problems and miscibility difficulties as pigments. However, theinventive metering device may be utilized in conjunction with any ofthese types of coloring agents for introduction within the targetplastic formulations.

Also, the liquids to be introduced within such plastics are not limitedto coloring agents (although such compounds are preferred). As a result,any liquid additives added within plastics may be utilized with such aninventive system. Included, without limitation, within the list ofadditives are clarifying and/or nucleating agents (as in U.S. Pat. Nos.6,102,999 and 6,127,470 to Cobb, III et al., both herein entirelyincorporated by reference), plasticizers, optical brighteners,antioxidants, acid scavengers, and the like.

OBJECTS AND DESCRIPTION OF THE INVENTION

It is thus an object of the invention to provide a new, easy to use,configuration of a liquid metering device for the introduction of liquidadditives onto a plastic pellets. As well, such an object includes theintroduction of liquid additives into molten plastics with the sameeasy-to-use device. A further object of the invention is to provide aliquid metering device which drastically reduces the possibility ofclogging within a feed pipeline from the liquid storage tank to thetarget plastic manifold flow channel. Another object of this inventionis to provide an easy-to-remove and/or attach feed line for introductionof liquid additives to target plastic formulations within a manifoldflow channel.

Procedures for the coloration of plastics is set forth in U.S. Pat. No.4,640,690, to Baumgartner et al., and U.S. Pat. No. 4,507,407, to Klugeret al., both entirely incorporated herein by reference, in which liquidpolymeric colorants are added to the resin before or during compoundingand polymeric addition reaction. These patents also provide the samedefinition and scope of the terms “thermoplastics” and “thermosets” asfor the inventive coloring applications. The term “plastic” is hereinintended to encompass both thermoplastic and thermoset compositions andarticles.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several potentially preferredembodiments of the invention and together with the description serve toexplain the principles of the invention wherein:

FIG. 1 is a diagram of one particularly preferred configuration andprocedure (for feeding into a plastic pellet stream) utilizing aninventive liquid metering device.

FIG. 2 is schematic cross-section (side view) of the attachment pointbetween the manifold flow channel and the injection port of the feedpipeline in unattached relation of one preferred configuration for theinventive liquid metering device.

FIG. 3 is a schematic cross section (aerial view) of the injection portof the feed pipeline in FIG. 2 along line 3.

FIG. 4 is a schematic cross section (side view) of the attachment pointbetween the manifold flow channel and the injection port of the feedpipeline in attached relation of one preferred configuration for theinventive liquid metering device.

FIG. 5 is a diagram of one particularly preferred configuration andprocedure [for feeding into a molten plastic or polyol (for polyurethaneproduction) stream] utilizing an inventive liquid metering device.

FIG. 6 is schematic cross-section (side view) of the attachment pointbetween the manifold flow channel and the injection port of the feedpipeline in unattached relation of one preferred configuration for theinventive liquid metering device.

FIG. 7 is a schematic cross section (front view) of the attachment pointbetween the manifold flow channel and the injection port of the feedpipeline in attached relation of one preferred configuration for theinventive liquid metering device.

DETAILED DESCRIPTION OF THE DRAWINGS INCLUDING PREFERRED EMBODIMENTS

As depicted in FIG. 1, a plastic pellet coloring system 10 is providedincluding a liquid storage tank 12 (in the preferred, though notrequired embodiment, the storage tank 12 contains liquid coloringagent), a liquid additive feed pipeline 18, a plastic pellet hopper 22,a plastic pellet feed pipeline 24, a pellet/additive mixing vessel 26,and a flow channel manifold 28. Thus, the liquid additive is transportedthrough a drawing pipe 14 (by means of a drawing pump 16, which alsofunctions as a metering pump), into the feed pipeline 18 which ispermanently attached to an injection port 20. The injection port 20 istemporarily attached to the mixing vessel 26 by a locking means(preferably a slide or spring lock mechanism, 37 in FIG. 4) andtransports the liquid additive in a controlled stream into the pelletstream which moves from the hopper 22 through the pellet feed pipeline24 into the mixing vessel 26. The hopper may include a mixing means (notillustrated) to prevent clogging of the mouth of the pellet feedpipeline 24. After co-introduction within the mixing vessel 26, themixture of liquid additive and plastic pellets is then transported to aflow channel manifold 28 in which the entire mixture may be exposed tosufficient heat to melt plastic pellets for further processing andbetter mixture with the liquid additive. The individual components ofthe coloring system 10 may be of any resilient material, such as metalor plastic. Preferably, the material is metal, such as steel, titanium,aluminum, and the like (more preferably aluminum) for components,although the feed pipelines 18, 24 are preferably of more flexiblematerial, such as polyvinyl chloride, polyethylene terephthalate, andthe like, tubing.

FIG. 2 depicts the mixing vessel 26 with the injection port 20unattached. The injection port 20 comprises the feed pipeline 30, aninjection feed line 34, a solid compartment enclosing the top portion ofthe injection feed line 32, a solid compartment enclosing the bottomportion of the injection feed line 31, an exit feed 35 (which introducescoloring agent away from the walls of the mixing manifold 26 to permitmore thorough mixing of the two different components), and a lockingindentation 36. The top solid enclosure 32 is integrally or temporarilyattached to the bottom solid enclosure 31 and is “male” configured in ashape in receiving relation to the mixing vessel 26. Upon locking intothe locking identation by a spring loaded pin (37, 38 of FIG. 4) theentire enclosure 31, 32 will not move out of the mixing vessel 26.Furthermore, the top solid enclosure 32 is larger in width and heightthan the bottom solid enclosure 31, all in relation to the width andheight of the internal structure of the mixing vessel 26, such that theentire injection port 20 will not be able to be inserted past a certaindistance into the mixing vessel 26. This is more specifically depictedin FIG. 4 wherein a locking pin 37, 38 has been inserted into thelocking identation 36 after insertion of the injection port 20 into themixing vessel 26. In such an arrangement, then, the liquid additive istransported into the injection port through the feed pipeline 30, intothe injection feed line 34 and out through the exit tube 35 into themixing vessel 26. The liquid additive then mixes with the plasticpellets moved from the pellet feed line 24 into the mixing vessel 26.FIG. 3 simply shows an aerial view along line 3 of the injection portitself.

As depicted in FIG. 5, a molten plastic or polyol coloring system 110 isprovided including a liquid storage tank 112 (in the preferred, thoughnot required embodiment, the storage tank 112 contains liquid coloringagent), a liquid additive feed pipeline 118, a molten plastic or polyolstorage tank 126, and a molten plastic or polyol feed pipeline/channelflow mixing vessel manifold 124. Thus, the liquid additive istransported through a drawing pipe 114 (by means of a drawing pump 116,which also functions as a metering pump), into the feed pipeline 118which is permanently attached to an injection port 120. The injectionport 120 is temporarily attached to the mixing manifold 124 by a lockingmeans (preferably a slide or spring lock mechanism, 122) and transportsthe liquid additive in a controlled stream into the molten plastic orpolyol stream which moves from the plastic storage tank 126 through themolten plastic or polyol feed pipeline 124, via a pumping and meteringdevice 128. The molten plastic or polyol feed pipeline 124 is attached(as noted above) temporarily to the injection port 120 to facilitateintroduction of the liquid additive into the continuous stream of moltenplastic and then further transported for further processing and bettermixture with the liquid additive. The individual components of thecoloring system 110 may be of any resilient material, such as metal orplastic. Preferably, the material is metal, such as steel, titanium,aluminum, and the like (more preferably aluminum) for components,although the liquid additive feed pipeline 118 is preferably of moreflexible material, such as polyvinyl chloride, polyethyleneterephthalate, and the like, tubing.

FIG. 6 depicts the mixing manifold 124 with the injection port 120unattached. The injection port 120 comprises the feed pipeline 130, aninjection feed line (128 of FIG. 7), a solid compartment enclosing thetop portion of the injection feed line 121, a solid compartmentenclosing the bottom portion of the injection feed line 132, an exitfeed (137 of FIG. 7), and a locking mechanism 122. To permit effectivesealing, and thus more effective transport with minimal leakage, seals134, 134 a are also provided on the outside surface of the solidenclosure 121. The top solid enclosure 121 is integrally or temporarilyattached to the bottom solid enclosure 132 wherein the entire enclosureis “male” configured in a shape in receiving relation to the mixingmanifold housing 127. The top solid enclosure 121 is larger in diameterthan the bottom solid enclosure 132 in order to permit introductionwithin the mixing manifold housing 127 in a complementarily shapedopening 133 such that the injection port 120 can not be inserted past acertain distance. Upon locking into the locking indentation by a springloaded pin (122, 122 a of FIG. 7) the enclosure 121 will not move out ofthe mixing vessel 124. This is more specifically depicted in FIG. 7wherein locking pins 122, 122 a have been activated to lock theinjection port 120 into place within the mixing manifold housing 127. Insuch an arrangement, then, the liquid additive is transported into theinjection port through the feed pipeline 130, into the injection feedline 138 and out through the exit feed 134 (which directs coloring agentaway from the walls of the mixing manifold 124 to permit more throughmixing of the two different components) into the mixing manifold 124.The liquid additive then mixes with the molten plastic or polyol.

If desired, then, to utilize a non-coloring or plastic productionsystem, such a configuration (as in 10 in FIG. 1 or 110 in FIG. 5) theinjection port (20 in FIG. 1 or FIG. 120 in FIG. 5) may be removed andreplaced by a similarly shaped article (not illustrated) with the samelocking mechanisms present but without any feed lines attached. Theresultant system thus would not feed any liquid additive into theplastic compositions, nor would any plastic be able to transport outthrough the unused, but filled, mixing manifold (26 of FIG. 4) or mixingmanifold housing (127 of FIG. 7).

There are, of course, many alternative embodiments and modifications ofthe present invention which are intended to be included within thespirit and scope of this invention.

What we claim is:
 1. A liquid transport apparatus comprising a manifoldhaving an external surface and an internal surface, and at least onedetachable liquid transport insert attached to a transport tube; whereinsaid mixing vessel comprises an opening therein to receive said at leastone detachable liquid transport insert; wherein said apparatus alsoincludes a locking mechanism to attach temporarily but securely said atleast one detachable liquid transport insert directly to said mixingvessel, said mechanism comprising a locking pin within said manifold andan indentation within said at least one detachable liquid transportinsert, wherein said locking pin is shaped in relation to saidindentation such that upon locking, said pin prevents said at least onedetachable liquid transport insert from being removed without firstremoving said pin therefrom; wherein said at least one detachable liquidtransport insert and said mixing vessel are configured in such a mannerwherein said at least one detachable liquid transport insert is incontact with both the external and internal surfaces of said manifoldwhen said locking mechanism is engaged; wherein said at least onedetachable liquid transport insert comprises integrally and internally ahollow portion, which is connected to but not integrally part of saidtransport tube, through which a liquid may be transported through saidat least one detachable liquid transport insert into said manifold whensaid at least one detachable liquid transport insert is attached to saidmixing vessel; wherein said hollow portion has a first opening and asecond opening, wherein at least one of said first and second openingsis located within said manifold and said second opening is locatedoutside said manifold; wherein said at least one detachable liquidtransport insert and said manifold opening are configured in such amanner as to permit receipt of said at least one detachable liquidtransport insert within said manifold opening upon insertion of said atleast one detachable liquid transport insert within said manifoldopening and, upon activation of said locking means, to prevent escape ofan appreciable amount of liquid outside of either of said manifold orsaid at least one detachable liquid transport insert; and wherein atleast one detachable liquid transport insert and manifold are configuredin such a manner when said locking means is in operation said at leastone detachable liquid transport insert extends within said manifold suchthat any liquid transported from said at least one detachable liquidtransport insert into said manifold is directed away from the internalwalls of said manifold.
 2. The apparatus of claim 1 wherein saiddetachable liquid transport insert further comprises means forpreventing the entry of the entirety of said insert within said manifoldupon attachment of said insert to said manifold.
 3. The apparatus ofclaim 1 wherein multiple detachable liquid transport inserts arepresent, wherein at least one of said inserts may be attached to saidmanifold at any one time.
 4. The apparatus of claim 1 wherein saidapparatus further includes a detachable plug insert wherein when saiddetachable liquid transport insert is detached from said manifold andwhen said detachable plug insert is attached and locked to said manifoldopening, said detachable plug insert prevents issue any liquid materialtherefrom.
 5. The apparatus of claim 2 wherein multiple detachableliquid transport inserts are present, wherein at least one of saidinserts may be attached to said manifold at any one time.
 6. A liquidtransport and mixing apparatus comprising a manifold, a mixing vesselhaving an external surface and an internal surface, and at least onedetachable liquid transport insert attached to a transport tube; whereinsaid mixing vessel comprises an opening therein to receive said at leastone detachable liquid transport insert; wherein said apparatus alsoincludes a locking mechanism to attach temporarily but securely said atleast one detachable liquid transport insert directly to said mixingvessel, said mechanism comprising a locking pin within said mixingvessel and an indentation within said at least one detachable liquidtransport insert, wherein said locking pin is shaped in relation to saidindentation such that upon locking, said pin prevents said at least onedetachable liquid transport insert from being removed without firstremoving said pin therefrom; wherein said at least one detachable liquidtransport insert and said mixing vessel are configured in such a mannerwherein said at least one detachable liquid transport insert is incontact with both the external and internal surfaces of said mixingvessel when said locking mechanism is engaged; wherein said at least onedetachable liquid transport insert comprises integrally and internally ahollow portion, which is connected to but not integrally part of saidtransport tube, through which a liquid may be transported through saidat least one detachable liquid transport insert into said mixing vesselwhen said at least one detachable liquid transport insert is attached tosaid mixing vessel; wherein said hollow portion has a first opening anda second opening, wherein at least one of said first and second openingsis located within said mixing vessel and said second opening is locatedoutside said mixing vessel; wherein said at least one detachable liquidtransport insert and said mixing vessel opening are configured in such amanner as to permit receipt of said at least one detachable liquidtransport insert within said mixing vessel opening upon insertion ofsaid at least one detachable liquid transport insert within said mixingvessel opening and, upon activation of said locking means, to preventescape of an appreciable amount of liquid outside of either of saidmixing vessel or said at least one detachable liquid transport insert;and wherein at least one detachable liquid transport insert and mixingvessel are configured in such a manner when said locking means is inoperation said at least one detachable liquid transport insert extendswithin said mixing vessel such that any liquid transported from said atleast one detachable liquid transport insert into said mixing vessel isdirected away from the internal walls of said mixing vessel.
 7. Theapparatus of claim 6 wherein said detachable liquid transport insertfurther comprises means for preventing the entry of the entirety of saidinsert within said mixing vessel upon attachment of said insert to saidmixing vessel.
 8. The apparatus of claim 7 wherein multiple detachableliquid transport inserts are present, wherein at least one of saidinserts may be attached to said mixing vessel at any one time.
 9. Theapparatus of claim 6 wherein multiple detachable liquid transportinserts are present, wherein at least one of said inserts may beattached to said mixing vessel at any one time.
 10. The apparatus ofclaim 6 wherein said apparatus further includes a detachable plug insertwherein when said detachable liquid transport insert is detached fromsaid mixing vessel and when said detachable plug insert is attached andlocked to said mixing vessel opening, said detachable plug insertprevents issue any liquid material therefrom.